National Transportation Library (NTL) -- In 2008 a new NTL was created through a merger with the US Department of Transportation Library. Subject concentrations include general transportation, surface, and water transportation. Special topics include: bridge construction and maintenance, driver studies, highways and highway safety, mass transit, merchant marine, pipelines, railroads, statistics, traffic engineering, urban transportation, and waterways.

NTL Integrated Search -- The site searches National Transportation Library Catalog and TRIS Online. The TRIS Online database contains over half a million records of published transportation research from the 1960's to the present, including technical reports, books, conference proceedings and journal articles. Currently there are almost 24,000 TRIS records with links to electronic copies of the full-text.